Gear-grinding machine.



C. S. GRANNIS.

GEAR GRINDINGv MACHINE. APPucATmN FILED APR.4,1912.

1 1 87,6 6. Patented June 20, 1916.

` ATTORNEY C. S. GRANNIS.

GEAR GRIND|NG MACHINE,

APPLICATION FILED APR. 4, 1912.

LIST/,616, l Pmenfedmme 20, 1916.A

8 SHEETS-SHEET 2.

C. S. GRANNIS.

GEAR GRINDING MACHINE.

APPLICATION FILED API1.4, I9I2.

' 11116111611 June 20, 1916.

8 SHEETS-SHEET 3.

C. S. GRANNIS.

GEAR GRINDING MACHINE.

APPLICATION FILVED APR.4,1912.

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. GRANNIS.

GEAR GFIINDINGl MACHINE. APPLICATION FILED APR. 4, 1912.

Patented June 20, 1916. l

8 SHEETS-SHEET 5.

C. S. GRANNIS.

GEAR GRINDING MACHINE.

` APPLICATION FILED APR. 4. |912. 1,187,605.16. Patented June 20,1916.`

8 SHEETS-SHEET 6.

C. S. GRANNIS.

GEAR GHINDING MACHINE.

APPLICATION FILED APR. 4, 1912.

Patented June 20, 1916.

8 SHEETS-SHEET I.

5 7 @A ,7 A A A IA C. S. GRANNIS.

GEAR GRINDING MACHINE.

APPL|CAT|0N FILED APR.4.191'2.

Patented June 20, 19164.

8 SHEETS-SHEET 8.

, inercia.

CHARLES S. GRANNIS, Y0F SYRACUSE, NEW YORK. .ASSIGNOR TO NEW PROCESS RAV HIDE COMPANY, 0F SYRACUSE, NEW YORK, A CORPORATION 0F NEW YORK.

GEAR-GRINDING MACHINE.

Specification of Letters Patent. Patgnged June 20, 1916.

Application filed April 4, 1912. Serial No. 688,496.

To all whom t may concern.

`Be it known that I, CHARLES S. GRANNis, of Syracuse, in the county of Onondaga, in the State of New York, have invented new and useful Improvements in Gear- Grinding Machines, of which the following, taken in connection with the accompanying drawings, is a full, clear, and exact description. I

This invention relates to certain improvements in machines for accurately finishing gear teeth to standard size and form after being cut and hardened in the mannerwell known to those skilled in the art.

The main object of my present invention is to provide means for accurately and uniformly grinding or finishing the previously cut gear teethl to the eXact forni required for perfect mesh with their companion gears so that they will run silently and smoothly without appreciable lost motion.`

Another object is'to render the operation of grinding or finishing the' teeth of a gear practically' automatic after such gear has been properly positioned in the machine yand to enable certain parts ofthe machine' to be adjusted to operate with the same degree of accuracy upon gears of different size or pitch.v

A still further object is to protect the operator from dust and dangers of breakage of the grinding elements by inclosing the 'latter in a' substantially dust-proof housing or protective'shiel Another object is to provide simple means for truing the abrasive surfaces of the grinding elements to the required form when Worn. f Other objects and uses relating to specific parts of the machine will be broughtoutin the following description.

j Inl the drawings, Figures l1, 2 and 3 are respectively a top plan, a front elevation and a side elevation of a gear finishing machine embodying the various features of my invention, a portion of the indeX- plate in Fig. 2 being broker away-to show the tape drum at the rear thereo-f. Fig. 4 is an enlarged transverse vertical sectional view through the upper front portion of themachine containing' the grinding elements taken on the line 4-4.-,. Fig. 3. Fig. 5 is an cnlarged vertical sectional view taken on line 5-5, Fig.- 2, showing the .means for` supporting and' operating the spindle upon which the gear to be ground is mounted. Fig. 6- is a diagrammatic view of the tape and tape drums and coacting parts for rolling the gear along a'plane tangential to the itch circle ofthe gear, the winding drum .eing shown in one eXtreme position by full lines and in its other 'extreme position by dotted lines. Fig. 7 is a top plan of the gear supporting spindle and carriage showing the edge truing device and gear centering lock and also the tapes, tape drums and index. Figs; 8, 9, 10, 1l, 12, 13, 14, 15, 16 and 17 are detail sectional views taken 'respectively on lines 8 8 and 9 9, Fig. 2; 10-10, Fig. 3; 1l.-11,Fig. l; 12-12, Fig. 2; 13-13, Fig. 12; 14.-14, 15--15 and 16-16, Fig. 3; and 17-17, Fig. 7.

The various moving parts or mechanisms of the machine are mounted upon a suitable supportingframe which preferably consists -of a hollow cast metal base-l-'having a rearwardly projecting offset -2 and an upwardly projecting bracket 3- terminating at its upper end, in laterally diverging arms -4- for receiving and supporting a pair of oppositely disposed angularbrackets or bearing plates -5--. These brackets -5- are "disposed in the same transverse vertical plane at opposite sides of the longitudinal center of the machine and are provided with journal bearings 6 for receiving a pair of revoluble shafts o r spindles -7- upon which are mounted suitable grinding elements as abrasive disks -8- of carborundum or equivalent material, said brackets being tiltable laterally for varying the angle of the disks and their supporting shafts as maybe required lin grinding gears of different pitch or different forms of teeth. For this purpose, the upper ends of the brackets are pivotally secured by bolts -5- to the front faces ofl their corresponding arms -4- in approximately the same horizontal plane as the central portion of tHe spindles -7-, while their lower ends extend downwardly some distance below said spindles and are concentric with the axes of their pivots and slidaljile along concentric bearings or guides -9-", having suitable graduations to indicate the angle or pitch to which the spindles and their grinding disks may be adjusted.

The portions of the brackets just above their lower concentric. edges are provided with laterally elongated slots --10n also them suitable pulleys '-12- which are scf` cured to the central portions of the shafts Y.or spindles -7- and adapted to be'conn nected by belts 13- to corresponding pulleys lllvon the upper end of an upright rocking frame -15-- This frame -15- is secured at its lower end to a rock shaft 1G- which extends transversely of the machine and is journaled in suitable bearings -17- on the rearwardextension upper end of the frame -15 carrying the pulleys #14.- to be adjusted forwardly and. rearwardly for tightening the belt. This adjustment may be effected by any suitable means consisting, in this instance, of a pair 'of sectional rods -l8- having their rear ends pivotally connected at -19- to the upper portion of the frame 15.- and their front. ends similarly connected by pivotal bolts 20- to brackets -Q- on the arms 4-, the sections of each rod being conn nected by a turn buckle -292- which is held in its adjusted position by lock nuts 23- as shown more clearly in Figs. 1 and 3.

The upper portions of the brackets and arms 4 are provided withlaterally elongated registering openings -24-' alined with the lower side of the pulleys ,-12- for permitting the passage of the lower sides of the belts l3- therethrough, saidopenings being also concentric with the pivotal bolts 8 which are located directly at the rear of the center of the pulleys so as to allow the brackets `-5-. to be adjusted laterally without throwing the pulleys T12- out of alinement with the companion pulleys -14-.

The bearings t5- are provided with -sleeve linings '-25- of phosphor bronze or equivalent material in which the spindles -7- are directly journaled, said sleeves being held in the bearings -6- against relative rotation or axial movement by one or more set screws v-QG- asshown more clearly in Fig. 2. c

The outer ends of the spindles -7- are reduced in diameter to form annular shoulders land for receiving suitable collars Q7- which are secured to said reduced portions by set screws -28- with their.

inner ends spaced apart from the annular shoulders for receiving interposed portions of independently revoluble adjusting sleeves '-29- and anti-friction end thrust ball `bearings whereby the spindle and sleeve are 65. held against relative endwise movement, and

at the same time permitting the sleeves to be adjusted rotarily relatively to their yrespective spindles. j

The inner ends of these sleeves -29- are provided with external threads engaging internal threads in the adjacent ends of the stationary bearing sleeves -25- foradjusting the spindles -7 andf\diskscarried thereby axially in grinding gears of different pitch.

The outer ends of the adjusting sleeves -29- are `provided with inwardly projecting tapering flanges fitting closely upon the *peripheries of the adjacent ends of the 'stationary bearing 'sleeves' -25'- and provided with graduations upon their peripheries coacting with a xed indicator on the bearing sleeves for indicating the degree of axial adjustment of the spindles and disks;

The bearing sleeves -25 are, preferably Jdivided, or split through one side in line with the set screws -26, the inner ends of'which are tapered and threaded and engaged with" corresponding tapered openings in 'the sleeve registering 'with the longitudinal slits so that when the setv screws are the inner faces of the outer bearings -6,

the latter being also divided through one side and drawn together by. bolts upon the inner sleeves, thereby aording a simplebut easily accessible means for adjusting the bearings to the spindle -to take up wear if necessary..

Eachspindle adjusting sleeve -29- is frictionally held against accidental rotation when once adjusted by means of one or more, in this instance` four, friction pins -30- which are mounted with an easy sliding lit `in axially extending sockets in the adjacent ends of the bearing sleeves -25- and are spring pressed into engagement with the inner ends of the spindle adjusting sleeves #29 by coiledsprings -31- interposed between the ends of the sockets and the inner ends-ofthe pins.

The abrasive disks ,-8- are rigidly clamped to the inner ends of their respective spindles -7.- by means of clamping collars PS2-f and S3- the collars -32 -32- and are secured thereto by clamping bolts -'-35- as best seen in Fig. 4, leaving an intervening annular space between the marginal edges of the collars of each pair between which the hubs ofthe abra'sive disks together with suitable pacln'ng washers are firmly clamped, the packing washers serving to prevent breakage of the disk by direct contact with the metal collars when tightening the latter upon the hub ofthe disk.

The marginal edges of the grinding disks 8* which are utilized for grinding or finishing the teeth to the desired form are beveled so that their inner and outer faces are disposed at an angle corresponding `to the angle of inclination of the spindles from a horizontal line, in this instance, twenty degrees, the outer grinding faces of the disks being disposed lateright angles to the axes of their respective spindles and therefore the inner adjacent faces are parallel which permits the adjacent faces of the disks to be brought into close juxtaposition.

The thickness of the beveled edges of each disk is slightly less than half the width of the space between the teeth of the gear` which is being ground so as to allow the grinding edges of both disks to readily enter the space at the root of adjacent gear teeth to give the desired width to such space according to the pitch of the gear, such width being regulated to a nicety by adjusting vthe spindles and their disks axially through the medium of the micrometer adjusting sleeves -29--, or if desired the disks -may be adjusted a sufficient distance apart to receive one of the gear teeth between them so that their outer grinding surfaces lmay operate upon the sides of alternate teeth which face each other as shown inFig. 4.

The grinding disks are inclosed within-a suitable dust proof housing -36- which is preferably divided verticallyin the plane of the axes of the spindles -7-- forming f ront and rear half sections, one of which, as the rear section, is secured hy bolts S7- to the upper ends of the arms -4- of the standard -3-, the other section being se cured by bolts -38- to the irst named section. operator against flyingdust but also against injury in case the disks should break, it being understood that these disksV are driven at comparatively high speed, and for this 1,

purpose the pulleys lll-rare secured t'o a horizontal shaft --l6- which is journaled in bearings -17- on the upper end of the frame 15- and is provided withv a tight pulley -14- adaptedto be connected by a belt to any available source ofpower not shown. v A

The lower side of the shield or housing -36- is provided with an opening siifiiciently large to permit a relatively small portion of the lower sides of the grinding disks -8- to protrude therethrough and also '-t0 permit' 4the gear to be brought in contadt with said disks even though the diameters of the latter may be; reduced fby wear and repeated truing.

Disk wing mechanism/.9; As previously vof the rock arm This housing not only protects the intimated, it is necessary to keep the l'grinding faces of the disks at the proper angle or at right angles to vtheir respective axes -36-, each rock shaft -43- vand cutting tool 40- being disposed in lines substantially parallel with the axis of the corresponding disk -8- so that when the rock varm -41- is moved back and forth about' the axis of the rock .shaft -43-,athecutting point of the tool will be moved at substantially right angles to the axis of the disk lor parallel and in Contact with lthe grinding face of said disk.

The cutting-tool '-40- is movable endwise toward and from the grinding face of its disk Within al suitable bearing 454- which is rigidly claLmped` in the upper end -41-, said cutting tool being held against rotation within said sleeve by means of a key 4G- which rides in a llengthwise key-way in the interior of said sleeve as the cutting tool is adjusted endwise. r

Each cutting toolis adjusted endwise by means of a rotary hand-operated sleeve 47- journaled upon areduced outer end of the cutting tool between a shoulder +48- and nut -49- by which the adjusting sleeve 4:7- is held against relative endwise movement on the cutting tool.

The hub of the sleeve -47- is threaded externally and engaged with internal threads upon the adjacent end of the relatively stationary sleeve #-455- so that by rotating the adjusting sleeve -47, 1 t will be screwed inward or outward according to the direction of rotation, thereby imparting similar endwise motion to the cutting tool to bring the cutting point into and out of contactr with the grinding surface of the disk.

The sleeve 47?- is provided withan in-` wardly projecting flange -50 telescoping with the adjacent end` of the sleeve 45- and is preferably tapered and provided withi graduations coacting with an index on the mustnecessarily be located outside of `the shield or housing 36e-v, while the cutting tool must extend into the housingin order ito contact with the grinding face of the disk and for this purpose the side of' the shield adj acent the cutting tool is cut away at -52- radially and axially of the disks to allow the bearing in which the cutting tool is mounted to play therein. When the `cutting tool is adjusted endwise into proper cutting contact with the grinding-faces of the disk by means of the adjusting sleeve -47-, the rock arm -41 is moved about the axis of its supporting shaft -43, the upper end of said rook arm being guided in suitable ways -54-- concentric with the axis of the shaft or spindle -43- so as to hold the cutting tool in exact parallelism with the grinding face of the disk in all positions of adjustment of the rock arm -4l-, said vguides 5aalso serving to hold the cutting tools rand rock arms against undue vibration or chattering.

lVhen the angle o'r the inclination of the disks and their supporting shafts or spindles are changed for finishing the teeth of gears of widely varying pitch, it is necessary to adjust the cutting tools to conform to the adjustment of the disks and for this purpose the lower end of the rock arm 4lis adjustable along and upon the rock shaft -13- by providing said shaft with a series of apertures 5G- arranged at different points in its axis for receiving the pivotal pin -.42-.

It is now clear that aside from the" fact that the grinding faces of the disks are previously formed or adjusted so as to travel inplanes approximately tangential to the involute curves of the teeth of gears of predetermined pitch, said grinding faces may be truedand kept at the proper angle by means of the cutting tools -40- and their adjusting device.

The rock arms 41 are adapted to be* operated by hand to/ move their respective cuttingtools -40-. across the grinding faces f of their respective disks butare returned to their normal start-ing positions to bring the cutting tpols out of Contact with thedisks by suitableJ plungers -57- having their front ends bearing against the rear ledges of the arms -41- and their rear ends slidcent sidesof the shield or housingf -36 and are spring pressed forwardly by coiled springs -59- within the bearings 58, the upper ends of the rock arms -41-' normally resting against a limiting stop G0- on the front ends of thev guides -54-.

In addition to the truing devices just described for keeping the outer faces of the grinding disks in planes at right angles to -K ter, said means consisting of a vertically dis` their respective axes, I provide suitable means forl truingl the peripheries of the disks and keeplng `them both of the same diameposeddiamond point cutting tool -61- adjustable verticallyin a suitable holder -62- which in turn is adjustable horizontally in a bearing 63'- on a transversely movable carriage G4- the cutting tool-l-being held in its adjusted position by a clamping bolt -65-, while the holder -62- is held` in its adjusted position by a clamping bolt m66- in the bearing -63.

The cutting points of the tools -40- for truing the outer grinding faces ofthe disks -8- are always disposed in a xplane co-incident with said grinding faces ready for use at any time7 while the point of the cutting tool -61- for truing the edges or peripheries of the disks is always located in the horizontal plane of the lowermost portions of the peripheries of said disks but normally to one side thereof and some distance in front ofthe gear when the latter is in position for grinding or finishing but may be moved rearwardly and laterally into position for truing the periphery of the disks by manipulating the carriage 64rin a manner hereinafter described.

Gear supporting and operating mechamsm.-1n order that the teeth of the gear as may be ground or finished to the desired involute form and size, suitable means is provided for bringing the gear and inder into perfect mesh with eachother with the abrasive faces approximately tangential to the involute curves of the teeth with which they are adapted to contact, ad-A disposed in a plane some distance below the lower edges of the grinding'disks and is operable axially thereof across and upon a forwardly and rearwardly movable bed -68- which in turn is supported upon a vertically movable cross head -69-, the latter being guided on upright ways -70- on the front side of the standard 4 3- as' shown more clearly in Figs. y2 and 3, thereby permitting the gear supporting spindle to be v moved horizontally in planes at right angles to each other across the lower grinding face of the disks and also vertically to and from the disks for purposes hereinafter more fully described.

Tlfe spindle G7- is journaled in suitable bearings 7 1-' on the carriage G4- at right angles to the vertical y/plane of the A axes of the grin-ding disks so as to extend forwardly and rearwardly of the machine in a plane 'some distance below the lower edges of said disks, the rear `end thereof being reduced and tapered for receiving a split friction sleeve -72- which is adapted to receive and support the gear -a-, ,the teeth of which are to be ground or finished. After these gears are hardened,

their central bores are accurately ground tothe desired gage andare adapted to be frictionally held upon the sleeve '-72'- by expanding the latter in the bore and for' this purpose I have provided a cap screw -73 which is tapped into the rear end of the tapered portion of the spindle and when screwed up tightly, engages the adjacent end of the sleeve 72- and wedges it tightly upon the tapering portion of the spindle, thereby tightening it in the bore of the gear.

The portion of the spindle in front of` y spindle W7-.extends forwardly some distance beyond its bearing -71- for receivling and supporting a tape drum -76- and an index plate 77.4, the latter'having a forwardly -projecting hub u on which is frictionally clamped a. radialply projecting arm 7S-f for a purpose presently described.

The tape drum -76- is loosely mounted on the spindle -67 and is provided with circular bearings of exactly the same diameter as the pitch -diameter of the gear to be ground, and to the peripheries of these bearings are attached one end of a pair of oppositely wound steel tapes 79- drawn tightly thereon and having their opposite ends attached to the peripheries of somewhat smaller drums -80- on opposite sides .of the machine; These smaller drums -80- are journaled in suitable bearings -81 on upright brackets S2- rising from the bed --68--l some distance to opposite sides of the spindle -67-, lsaid drums -80- having their upper sides disposed in substantially` the same horizontal plane as the upper side of .the peripheries of the drums 7G- so as to hold the tapes'.7`9-` in the same horizontal plane tangential ,to the pitch circle of the gear for the purpose of Aimparting rolling motion to the gear and itsV supporting; spindlev as the carriage. v .-6flis reciprocated transversely of the machine. v The 'drum #-.764- is provided with coaxial circular be'arings arranged side by -side in close proximity and of the same diameter as thatof the pitchlcircle f the gear and upon which thejinner ends ofthe tapes are wound in opposite directions and secured thereto in Iany well known manner. V The' outer ends of the tapes are rigidly secured by suitable fastening means to the peripheries of the drums -80- which are` the disk alined with the corresponding circular bearings of the drum 76- and adjustable rotarily to draw the tapes tightly in a planev tangential to the pitch circlel of the gear.

AForthis purpose the spindles as -83- to which the drums -80- are secured are provided with Worm gears -84, rigid thereonv and engaged by suitable worms -85. These worms are mounted upon separate shafts or spindles -86- which are journaled in the bearings -81- at right .angles to the spindles -83- and extend Aoutwardly beyond said bearings for receiving a suitable operating member 87 and friction disks -88- and f89-.

The operating member -87- preferably lconsists of a hand wheel having a radial web loosely journaled `upon the spindle friction disks B8-'f and ^-89-, the disk sel .=-86- and frictionally held between the l 88- being secured to the spindle -86-,

while the disk -89- is mounted upon an angular portion 9oofsaid spindle and is adjustable axially bymeans of a nut ,-91- so as to increasethe friction upon -87- when necessary. The ob-` ject of this slip friction connection between the operating member -87- and spindle 8G- iste prevent excessive stretching or breaking of the tapesduring the tightening adjustment, and at the Sametime the worm and gear affords a positive lock to hold the tapeslin their tightened condition.

t is now apparent that when the gear is properly adjusted or centered for grindin coactionl withthe grinding disksf-S- an the carriage 64ereciprocated, the tapes -79- operating upon the drum -76- will cause the gear to roll along the plane ofthe i j tapes tangent to its pitch circle in substantially the same m-anner as though it were in causing the teeth of the gears to be ground in involute curves of standard form and size.

The movement of the carriage 464- is sufliciently slow to effect the proper grindupon another adjacent set and so on until all of the teeth of thegear are ground to the desired form and size. For this purpose, the circular indexplate -77- is rigidly secured to the reduced frontend of the gear sup-I porting spindle -67- by means of a set screw 92; and has its periphery provided ing in number to the number-of vteeth of the gear to be ground and for interlocking en- 'mesh with a ixed toothed rack,| thereby l ing of the set of teeth which may be in conwith a series of notches -98- correspond-v gagement with a suitable pawl ---941`4 which 1g@ is pivotally mounted upon afradially projecting arm 95- on the front face of the drum 7G-'- as shown more clearly in Figs. 2, 6 and 7 Vfor locking'` the tape druml to swing in the direction of movement of the carriage G4- and having its lower end projecting. into the path of a suitable ylug 9S- on the pawl V 94rso as to trip said pawl from interlocking engagement with the index plate #-7 7 when the carriage 6471 approaches the limit of its starting position or just before the lgear reaches the position shown byY dotted lines in Fig. 6, it being understood that as the carriage and gear! supporting spindle mounted 'thereon are moved 1n one direction, said spindle and `parts carried thereby are rotatedin the opposite direction. by means`of the tapes --7-9- so that as the carriage approaches the limit of its return movement, or to the right of Fig. 6, the pawl -'-94-f will be moved bodily to theleft of said figure from the position shown by dotted 'lines until it is engagedv and tripped by the tripping pawl 96- which is held against movement in one direction by contact with a shoulder -99 on the bar .-97.

Just before the pawl Q/1 -is forced from .its locking position by contact of the lug -98- with the ytripping pawl -96-, the radial ar 7S- is brought into contact `with a ixe stop 100- on. the bracket 82- at the right of Figs. 2, 6 -and 7 and.

as the carriage continues its return movement, the pawl .94- will b'e carried slightly beyond the tripping pawl -96- to the position shownb dotted lines in Fig. 6 and thereby release and at .the Sametime the index vplate will be held against rotation is forced by a spring -944- into the next s,succeeding notch -93- of the index'plate:

to again lock the drum -7 .6- to the spindle, this additional movement of the carriage after the pawl has been released being sufficient to shift the gear rota'rily one tooth space and during such additional movementI ment of the 'carriage #-64- to the left- 35 causes the tapes -79-to roll the gear to the- .right along the tangent of its pitch circle coincident 'with said tape, thereby rocking the arm -'92- downwardly and to the left which is mounted upon an adjustable bar -102- on the front of the forwardly and vrearwardly movable carriage -68-, thereby causing said arm 92- to turn upon the hub of the index plate -76- which together with the spindle supporting gear continues torotate to the right until the carriage is moved to its extreme forward position to the left a suiicient distance to grind the gear tooth fromits root to its point as shown by full'lines in Fig. 6.

The object in limiting the movement of the arm -92- by the stop lOlis to keep l to travel to the right against the tripping pawl -96- which is free to move to the right out of the path of the shoulder -98-, thereby permitting the pawl -94- to remain in locking engagement with the index plate during the movement of fthe carriage 64- to its extreme left-hand position and return until the pawl -94- is again tripped on the return'in the manner previously described. f

In placing the gear -w-aupon its supporting spindle 67'- it may be centered tol `bring itsteeth in proper registration with the grinding disks by means of a centering or locking bolt -103- whichis' slidably tmounted radially ,of the gear and its sup,- porting spindle -upon a suitable support #-104.- and is adapted to be Springv pressed into the space between the teeth of a gear by fmeansl of a coiled spring 105- inter'- posed between a shoulder on the locking bolt and the end of the socket in which the boltis slidable, said bolt being also. provided with a radially projecting pin -106- movable in a slot -107- in the outer end of the bearing in which the vbolt is movable and is adapted to be turned with the bolt` to engage the end face of said bearing to lhold the bolt out of interlocking engagement with the' `gear teeth during-the grinding operav..tion,` the outer end of the bolt being"pro vided with a hand piece @108,- by which it may be withdrawn endwise against the ac-l tion of the spring -104 -v and turned so as to move the pin -106 into and out of registration with its slot -107-. The support -105 upon which this centering boltl is mounted' lmay also"be adjusted transversely of they axis of the gear audits supporting carriage -64l-- and held in its adjusted position by aclamping bolt -110- as shown more clearly in Fi fr. 7, the object of such adjustment being to properly position the centering bolt 1 03- for gears of dilferent size.

In the initial'adjustment of the machine for grinding a greater or less number of gears of the same size, thecarriage mBaw- Ais adjusted to the right in such a position as will bring the lug -98- on the pawl -*94- at )some point between the limitv of its movement to the right 'and its tripping position with -one of the toothed spaces of the gear in 'registration with the centering bolt -lOf whereupon said bolt is released to enter such spacev and suitable means provided for;l determiningthe exact position of the carriage 64- while the gear is still held by the centering bolt, and for this purpose I have provided the forwardly and rearwardly movable bed 68%- with an upwardly projecting armv 'lllinA which is mounted an adjusting screw 112- held in place by va lock nut 1137.- so that its inner end forms an abutment inline with the adjacent end of the carriage. Between this abutment and adjacent end ofthe carriage is fitted a gagefblock -114- which has been previously made to the width corresponding to the distance between the carriage and vabutment when the centering pin is engaged with the gear in the manner previously described', -leaving suflicient clearance between said carriage and abutment when the gage block is removed to permit the return o f the carriage to its starting position to trip the pawl -94- and shift it into engagement With the next succeeding notch of the index .plate -77- after the centering pin has been withdrawn from engagement with the j gear.' In 'other' v 'vords during 'the grinding operation, the locking bolt -103`-' is with- .drawn and locked in its inoperative position and the gage block --11l-,4 is also with.- drawn and laid aside to permit the carriage G4- to be reciprocated from one extreme to' the other of its movement as determined by the position of the connecting rod 439- on the crank disk -137-.

After the teeth of each gear have been properly ground and the gear removed from the spindle, the gage block -1-1l--'v is placed in operative position between the abutment -112-- and adjacent end of they carriage which is adjusted to abut against the inner end of. the gage block when the latter is in contact with ,the abutment, whereupon another gear to be ground is placed upon the lspindle and centered bv the locking bolt +103-, the gear being then tightened upon 'thesspindle by adjusting the bolt -73-` whereupon the centeringv bolt -103 is withdrawn and locked in its inoperative pothe assurance that the teeth of the gearl afwill be ground to standard form and size by the grinding elements.

The carriage 64 is preferably reciprocated by a mechanism driven by the shaft -16- -on the upper end of the rocking frame -l5-- and for this purpose I have provided one end of said shaft with cone pulleys -116- adapted to be connected by a belt *117- to another set of-cone pulleys 118- on ank underlying shaft ,--119- which is also j ournaled in suitable bearings upon the rocking frame '-15- as shown more clearly in Figs. l, 2 and 3.

Secured to theopposite orleft-hand end of the shaft -119- is a spiral gear e120- meshing with a superposed spiral gear 121- which is mounted upon one end of a flexible shaft -122-, the latter being journaled in a gear case -1'23- inclosing the gears -l20- and 121- and to the adjacent end of the flexible shaft l22-. This flexible shaft -v-122- extends forwardly and has its front end telescoping within and keyedy to an axially movable rotary sleeve -124- as shown more clearly in Fig. 9, said sleeve. being journaled in a suitable bearing or gear case 125- on the left-hand side of the vertically movable cross head -69 as seen in Figs. 2 and 3D The front end of the sleeve 124- is provided with a clutch section,-126 movableinto and out of engagement with a corresponding clutch section *127- on the adis journaled in a suitable bearing 129- in the gear case -125- and meshes with a worm gear -l30-- also mounted within said gear case.

The opposite or' rear end ofthe clutch `sleeve 124- is provided with an annular groovel -131- for -receiving yan eccentric bearing -132--` on the inner end of a lrotary. spindle -133-, said spindle being The worm gear- 13042` issecured to an upright shaft -136T- which Vis also jour-y .,naled in the gear case -125- as shown more clearly in Fig. 8 and is provided at its upper end with a cam disk 4or eccentric -137- having a radial slot -138- in which is adjustably secured al pivotal bolt -139-' for receiving the adjacent end of a connecting rod -140-. The opposite end -of this rod 4-140-" is pivotally connected at'.

141- to the carriage Gaf-for reciprocating'said carriage las the disk 137- is rotated, the connections between the connecting rod 140- and disk -v137--- being adjusted so as to impart the desired degree of movement to the carriage.

The carriage -64 is connected to the rod 140- in such manner as tocause the carriage to' move a greater distance to the right-hand side of the vgrinding disks than to the opposite side. so as to provide for the eXtra movement required to shift the gear rotarily one tooth space at each return of the carriage to its starting position as previouslypointedfout..

It is sometimes necessary to move the car'- riage voluntarily vinstead of automatically and for this purpose' the shaft or spindle -136- is extended downwardly some distance below the'worm gear -130- for receiving a bevel gear 142- and a clutch member #143-, the latter being spring pressed into engagement'with a .coacting clutch section 14A- on the lower end of naled in a suitable bearing -149- on the gear ease 4125-, thevfront end of the spindle being angularv in cross section for receiving a hand crank or other suitable tool by which the spindle -136-' maybe rotated to reciprocate the carriage through the medium of the clutch sleeve 143- and gears m142- and -147.

' As'previously stated, the carriage ,687-l is movable forwardly and rearwardly and is also adapted to be raised and lowered to enable the gears to be placed on the spindle,v

while ,the grinding elements are revolving and for this purpose, the carriage -68- is lprovided on. its lower side with a toothed rack -150'-' meshing with a worm 151, the latter being securedto a forwardly and rearwardly extending shaft -152- which is' journaled in suitable bearings on the vertically movable cross head '-69- and its front end is preferably angular in cross section for kreceiving asuitable crank or equivalent tool by which this forward and rearward adjustment of the: carriage 68- and gear supporting spindlfe' may bev/affected voluntarily.

The meansl for adjustingA the cross head -69 vertically consists of a diagonally disposed horizontal shaft -153 journaled upper end of this shaft -157- is journaled .in a suitable bearing 158- in the cross head G9- and its lower end is screw# threaded at -159 and engaged with an internally threaded sleeve or hub -160- in .the top of the base -1- of the main supporting frame so that as this shaft is rotated the cross head and parts carried there; by will be raised or lowered according to the direction of such rotation. v

The operation of my invention has been fully set forth in theforegoing description and although I have'described Vone particular construction for carrying out the various objects, it is evident-that the details of j such construction may be varied materially without departing from the spirit of my invention and therefore I do not limit myself to the Aexact construction shown and described.

What I claim is:

1. In a gear grinding machine, a supporting spindle for a gear blank, means for reciprocating said spindle radially in parallelism with its axis, additional means coacting with the first named means for rotatl ing the spindle, and thus imparting a rolling motion to the gear/blank along a plane tangential to the pitch circle of' the gear and parallel to the plane of movement of the spindle, a pair of rotary grinding disks having their active edges intersecting said plane, and means for rotatingsaid disks.

i. 2. In a machine for finishing gear teeth, a pair of rotary grinding disks having opposite faces disposed in planes convergingtoward the periphery at one side, said grinder having parallel grinding faces'spaced apart at the grinding point to enter different tooth spaces of a gear, means for rolling a gear along a tangent to its pitch circle and at right angles to a medial plane between said faces, and additional means for adjusting the gear into and out of mesh with the grinder.

3. In a machine for grinding gear teeth, a pair'of rotary spindles disposed end to end at an angle to each other, circular grinders carried by the spindles, means for adjusting pitch circlerintersecting the peripheries of the grinders, additionalv means for moving,- the gear supporting means at right angles to a medial plane between the grinders, and

further/means for rotating the spindle to lroll the gear along a tangent'of its pitch circle at right angles'to such plane.

4. In a machine for grinding and finish ing the teeth of gears, a pair of rotary grinder-supports, means 4for adjusting said supports to different angles relative to each other, separate means for adjusting the supports axially, a rotary gear-support adjustable to bring the pitch circle of the gear Within the periphery of the grinders, a drum coaxial with the gear-support and having a circular bearing of the same diameter as that of the pitch circle ofy the gear to be ground, lexible members having one end Wound in opposite directions around and upon said bearings and their opposite ends extending in the same tangent therefrom and at right angles to a medial plane kbetween the grinders, holding means for said opposite endsV of the members, and

Vmeans for moving the gear support and drum parallel With said tangent.

5., A gear grinding machine having arotary grinder and meansfor rolling a gear along a tangent of its pitch circle transversely of and in mesh with the periphery of the grinder, said means including a' drum having a circular bearing of` the same raldius as that ofthe pitch circle of the gear to be ground, and a flexible member wound thereon and extending tangentially therefrom.

6. A. machine for nishing gear teeth comprising Separate axially ladjustable vrotary grinding disks, amechanism for reciprocating a gea-r transversely of its axis and imparting to it a rolling motion along a plane tangential to its itch circle.

7 A machine for 'Shing gear teeth having. means for rolling a gear along av plane tangent to its pitch circle, said means comprising circular bearing members coaxial vvith and of the lsafmeradius as the pitch circle of the gear, and tapes oppositely Wound on said bearing members,

8. In a machine for fnishlng gear teeth, a rotary gear-supporting spindle having circular tapereceiving faces concentric there- .with and of the same radius as the pitch circle of the gear, tapes Wound at one end upon said surface, separate device for holding the rotary gear-supporting-'spi'nd e, means o1l movlng the spindle axially, separate means for reciprocating the spindle radially a straight line, additional means for imparting a rotary motion to lthe spindle at such speed as would impart a rolling motion to the gear along a plane tangent to its circle and parallel with the reciprocatory movement, additional means for adjusting the spindle in a plane at rightangles to its reciprocatory movement, and rotary grinding disks having its periphery traveling through rthe pitch circle of the gear.

10. In a machine for finishing gear teeth, a gear-supporting spindle, means for reciprocating the spindle radially in a straight line, additional means for rotating the spindle in opposite directions as it 1s reciprocated, a grinder meshing with' the teeth of the gear for engaging and centeringa gear ,upon the spindle to bring its teeth into proper registration with the glrlnder.

In witness whereof I have hereunto set my hand on this 30th day of March, 1912. CHARLES S. GRANNIS. Witnesses:

H. E. CHASE, E. S. TUCKER. 

